More than 45% of women exceed guidelines established by the Institute of Medicine (IOM) for gestational weight gain (GWG). Women who begin pregnancy overweight or obese are more likely to exceed the IOM guidelines than are normal weight women. Excessive (GWG) is associated with negative obstetric outcomes, increases the risk of obesity in offspring and leads to greater postpartum weight retention. Preventing excessive GWG can improve obstetric outcomes and may lead to improvements in the treatment of obesity for women. However, interventions to prevent excessive GWG have not been consistently successful, and there is a need to identify modifiable behaviors related to GWG to support the development of effective interventions to prevent excessive GWG. Loss of control over eating (LOC), or the ingestion of food coupled with a sense of being unable to control the quantity eaten, is strongly associated with weight gain and is modifiable. LOC also is related to depressive symptoms and psychosocial distress which also are associated with weight gain. Thus, the goal of the proposed study is to assess relationships among GWG, LOC and psychosocial distress. Pregnant women (N = 300) who are overweight or obese prior to pregnancy (i.e., pregravid BMI>25) will be recruited from obstetric clinics at a local women's hospital. Women will complete structured, clinical interviews including the Eating Disorder Examination (EDE) and the Structured Clinical Interview for DSM- IV diagnoses (SCID) to document LOC and depressive symptoms at the end of the first trimester of pregnancy. Measures of perceived stress, social support, calorie intake, physical activity, and other factors related to GWG also will collected in first trimester. Assessments of LOC, psychosocial distress, eating and activity will be repeated monthly by telephone between weeks 20 and 36 of pregnancy. To document postpartum weight retention, women will be interviewed again at 6 months postpartum. Weight will be assessed at each in person visit and GWG abstracted from women's medical charts at the end of pregnancy. The proposed research is an extension of previous work conducted by the investigative team, and will provide important data on modifiable mechanisms for excessive GWG. Understanding behavioral mechanisms of excessive GWG is likely to inform interventions to prevent excessive GWG and thereby improve the health of mothers and children.